I have a new P238 as well. Mine is very smooth when chambering a round. Try this. Lock open the slide with no magazine inserted. Insert loaded magazine and then use the slide release lever to close the slide. It should chamber a round with no hesitation at all. If it still refuses to chamber a round, simply give the slide a bump with your hand to help it chamber the round. Normally, you "slingshot" the slide to chamber a round. This is grasping the rear of the slide, after the slide is locked open, and pulling back on the slide, and letting go. The recoil spring slams the slide shut with force. This is the accepted way to chamber a round. With many pistols, its not recommended to close the slide with the slide release lever, but the P238 can be closed this way with no damage to the slide stop. The P238 is a very high quality pistol, and there shouldn't really be anything you can do to help the "smoothness" It should already be a nicely polished action from the factory. Many people will tell you to take a Dremel and polish the feed ramp on the barrel with some rouge, but the Sig usually comes very well "slicked up" from the factory. You haven't said if you have actually fired the pistol yet. If you haven't, rest assured that it will perform perfectly, even if you have to give it a little help to chamber the first round.